Haha, the M3 does sound nice with the Supersprint in fairness but indeed not a cheap exhaust. I was lucky to get it cheap from the factory in Italy as an ex demo and test exhaust. Its full Supersprint V2 stepped manifolds, 100 cell race cats, center section and lightweight race rear section. I've a CSL carbon airbox then too that makes noise at the other end :)
Those systems are lovely, Nige! Reckon the first type with the rolled tips would be the pens if go for.
How much roughly would a full turbo back prestige system be?